Powertrain, generic (extended)

P2CF9 Belt Integrated Starter Generator Belt Tensioner Control Circuit/Open

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

P2CF9 applies to belt starter-generator systems whose belt tensioner is moved by an actuator rather than by a spring alone. Patents describe the idea: Ford raises belt tension for engine starts and boost and lowers it while charging (US 9,297,445, with an actuator that falls back to high tension when unpowered); a Hyundai/Kia patent uses a solenoid with three tension stages (US 10,648,544); a later Ford patent switches an active tensioner between high and normal positions (US 12,577,903). P2CF9 means the controller sees an open or otherwise faulty drive circuit to that actuator. No carmaker has published the code; hydraulic tensioners such as on FCA eTorque have no control circuit. Possible effects: belt slip on restart, noise, disabled stop-start or assist, MIL.

Likely causes

Broken wire or loose connector in the tensioner drive circuit
Open coil or motor winding in the tensioner actuator
Output stage in the controlling module failed

Symptoms

  • Belt squeal or slip during automatic restarts
  • Stop-start or electric assist disabled
  • MIL or system warning on

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€50–700
Time0.5–3 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

bisg belt tensionerwiring harnesshybrid control module

Related codes

P2CFAP2CFBP2BA3P0A1E

References: patents.google.com, patents.google.com, patents.google.com, law.cornell.edu.